Shot shell



y 1935. J. M. OLIN ET AL 2,008,922

SHOT SHELL Filed Jan. 28, 1951 5 Sheets-Sheet 1 July 23, 1935. J. M. OLIN El AL SHOT SHELL Filed Jan. 28, 1931 5 Sheets-Shet' 2 III III July 23, 1935. J. M. OLIN ET AL SHOT SHELL 5 Sheets-Sheet 3 Filed Jan. 28, 1931 L A n m L O M l SHOT SHELL Filed Jan. 28, 1931 5 Sheets-Sheet 4 July 23, 1935.

J. M. OLIN ET AL SHOT SHELL Filed Jan. 28, 1951 5 Sheets-Sheet Patented July 23, 1935 UNETED STATES PATENT QFFEQE SHOT SHELL Application January 28, 1931, Serial No. 511,669

5 Claims.

This invention relates generally to shot shells, and more particularly to tubes therefor, and the process and apparatus for making the same.

It is customary in the formation of tubes for shot shells to roll sheets of paper which have been covered with paste or other adhesive upon a mandrel so that the wall of the tube is composed of a number of convolutions of the paper. The paper alone, however, does not possess all the qualities which are required of a shot shell tube and accordingly, such tubes have heretofore been impregnated with paraffin, waxes or mixture of the two so as to waterproof the same and render them fireproof against the hot powder gases. When the shell is fired, the hot powder gases moving outwardly through the shell wall dissipate their heat to the wax and transpose it from the solid state to the liquid, so that the latent heat of the wax is taken advantage of in maintaining the temperature of the tube below the point of ignition, thereby preventing charring in the tube. Upon the explosion, however, the wax is liable to become cracked so that the powder gases are permitted to penetrate the pores of the paper following an irregular path, which results in a honeycomb structure, thereby weakening the tube to such an extent that it is incapable to withstand the force of the powder gases in the interior thereof, and, consequently, the tube is liable to become ruptured.

Parafiin and other waxes being usually of a crystalline nature possess certain disadvantages which it is an object of this invention to overcome. Among the disadvantages of a crystalline material in this relation is the fact that the crystalline structure defeats the natural flexibility and pliability of the paper and reduces the entire shell to a structure more or less brittle and having substantially the same properties as the wax. It is, of course, well-known that when a shot shell is fired the tube must expand to meet the Walls of the gun chamber, the paper alone" not having suflicient strength to withstand the tremendous pressure of the gas generated during burning of the powder charge. Consequently, the treatment of such shot shell tubes with wax, although adequate to prevent the penetration of moisture and hot powder gases thru the wall of the tube, possesses the disadvantage of precluding such expansion of the tube upon firing the shell, which obviously will result in rupture to the tube and permit leakage of the powder gases, and thus interfere with the functioning of the gun.

- Still another disadvantage in impregnating shot shell tubes with crystalline substances, such as waxes, is the fact that such waxes must be reduced to a substantially liquid form, requiring the application of considerable heat, before they can be successfully applied to the paper. It is Well-known that paper when exposed to such temperatures as that of molten waxes, shows a substantial decrease in pliability, elasticity, and strength, and since in this particular use, it is necessary that the paper possess its maximum pliability, elasticity and strength, the use of such waxes as an impregnating substance is antagonistic to the good qualities of the paper employed. Furthermore, after the hot waxes have been applied to the paper a considerable contraction thereof takes place which has been found to set up internal stresses in the paper which increases the tendency toward rupture uponfiring. Moreover since the characteristics of paraffin and other waxes are not such as to preventthe passage of gases, or in other words, the waxes are not entirely impervious to the passage of gases and, furthermore, since a number of fissures are liable to occur in a wax coating, upon cooling thereof, it has been found that such waxes are not as efficient in the prevention of the penetration of hot powder gases as is desirable. Accordingly, in such shells and tubes which have been impregnated with paraflin or another wax, it has been found that upon firing thereof the walls of the tube become punctured and thus permit the escape of gas as well as loss of firing pressure.

The object of this invention is, generally stated, to provide a material for the treatment of a shot shell tube paper which will not possess the disadvantages hereinbefore discussed.

Another object of the invention is to provide a shot shell tube having an inner layer of plastic substance.

Another object of this invention is to provide a process and apparatus for applying plastic substance to shot shell tube material during the process of forming the tube. 1

A further object of this invention is to provide a device for applying a coating of stearine pitch to the necessary area of the paper which goes to form the shot shell tube.

A more specific object of this invention is to provide a shot shell having a gas sealing medium in the wall thereof.

A further object is to provide a composite sheet of material for making shot shell tubes.

A further object is'to provide a shot shell tube having an isolated body of a gas sealing medium extending therearound,

Another object is to provide a shot shell tube having an elastic cooling medium in the wall thereof.

Other objects of this invention will become apparent to those skilled in the art when the following description is read inconnection with the accompanying drawings thruout' the various views of which like'reference characters denote the same parts, and in which Figure 1 is a, view in side elevation of a 'shot shell tube formed in accordance with thisinvention;

Figure 2 is an enlarged detail viewillustrating the disposition of a layer of plasticsubstance in the wall of a shot shell tube;

Figure 3 is a plan view of a sheet of tube forming material having a portion thereof covered with a plastic substance in accordance with this a invention;

Figure 4 is a View of the sheet illustrated in Fig. Bafter being rolled to form a tube;

' Figure 5 is a sectional view in side elevation of a machinefor coating the sheets as illustrated in Fig. 3;

: Figure 6 is a planview of the machine illustrated in Fig. 5; V

. Figure '7 is a plan view of a modified form of a machine for coating sheets as illustrated in Fig.

Figure 8 is an end elevation of the machine illustrated in Fig. '7;

r Figures 9 to 13 inclusive, arediagrammatic illustrations of modified means for carrying out the process of this invention.

vThis invention contemplates the provision of a gas sealing medium in the wall of the shot shell tube. The criterion for such a medium would, of

:forming material.

course, be a wall of liquid,.such as, for instance,

- water between successiveconvolutions of the tube Since; however, such a liquid 'cannot be practically employed for this purpose the. tube is formed. It may be preferable to dis-- solve the plastic substance such as stearine pitch H in a suitable solvent and apply'the solutionito the g 1 paper to, be thus treated and thus coating the it has been found that any suitable plastic substance such as a pitch, is adaptable'for this use.

In accordance with this invention a plastic substance which may be, for instance stearine pitch, is applied to the paper or material which goes to form a tube of the shot shell. A plastic substance,

such as for instance stearine pitch,.possesses all the advantageous qualities necessary for render- :ing the.v tube more impervious to. moisture and hot powder gases. Moreover such a plastic substance "does not in any way afiect the physical characteristics of the paper or other material of which same. Of course, any suitable solvent may be employed, for instance carbon tetrachloride, benzol,-naphtha, etc., but for the purpose of illustra-- tion carbon tetrachloride will be used. Such a solution lends itself to applicationby means of a number of different types of apparatus, such as foriinstance by rolling, brushing, spraying or stamping. It is oftenpreferable, however, to apply the stearine pitch without the use of such a solventand in this case it becomes necessary to heat the pitch slightly abovenormal temperature under which circumstances it becomes of high viscosity and is readilyapplicable. In this form,

however, the. stearine pitch is most readily applied to the tube .forming material by rolling.

It is not necessary'to coatt'he entire sheet of the tube.

material which goes to form the tube of the shot shell since if there exists a layer substance which extends completely about the circumference of the tube, this will be suflicient to prevent the penetration of moisture as well as the pask sage of hot powder gases. For this reason it has been deemed preferable to apply the stearine pitch only to such portion of the strip of tube .forming paper or: other material as will be necessary to form one complete convolution within The pitch-covered convolution is preferably disposed near the inner Wall of the tube and for this reason the tube forming material should take one complete convolution before that portion carrying the stearine pitch is wound number of convolutions of material are required coated convolutions of material on both sides of the coated convolution in a shell constructed in strict, accordance with this. invention. It is, nevertheless, within ;the =scope of this invention to completely cover 'or thoroughly impregnate .the

"entire strip ofimaterial which goesto form all the convolutions of such a shot shell tube.

It is apparent that such a plastic substance as stearinepitchmay be readily applied to the paper or-other material for forming the shot shell tube at any time-prior tothe rollingprocess thereof. This invention however, contemplates I the, application of such stearine pitch to the. tube 15 thereupon. Thus since in shot shell tubes a ntorform the: completed tube, there will exist unforming material by the provisionof a pitch applying deviee upon the tube forming machines as heretofore known.

Referring now to? thezdrawings. and particu I larly to Figs. 1 and 2 thereof, it will be observed that the shot shellof this invention comprises a' plurality of convoluti'ons I of tube formingma- 'terial, such as'paper, as clearly illustratedin Fig.

2. Between successive convolutions I and the inner wallof the :tube a layer of plastic substance 2, such as for instance stearine pitch, isprovided to'prevent "the penetration of ,moisture and render the tube impervious to hot powder gases.- It

will be understood that the layer 2 of stearine pitch extends completely about the circumference of the :tube and preferablyislapped upon itself for a short distanceto insure 'the'seal.

Inthe process, of rolling shot shell tubes as heretofore known ithascommonly been the practice to: roll a sheet of tube forming material, such as paper, having a width equal. to the combined circumference of the plurality of 'convolutions,

which-go to form. thefim'shed'tubeanda length equal to thelength. of a plurality of finished shot 7 shell tubes.

Referring to Figs. 3 and 4,-it will be observed that a sheet of paper 3 is of substantially rectangular form, the width dimension a--b I thereof being equal to the length of the stripof material embodying the tubeof the shot shell il lustrated inFig. 1 as if the same wereunrolled.

For the purpose of illustration, the length b-c is, of course,apparent from-Fig: 3"that thearea covered by the stearine pitch extends completely Thus'on the sheet of paper 3 a portion,

' across the sheet of paper 3, it may here be pointed rolls 6 and I.

out, however, that the application may be made to a plurality of areas having lengths substantially equal to the length of the powder and shot charge to be placed in a completed shot shell. Under the latter circumstances a space would exist between adjacent areas having an application of stearine pitch intermediate of which space the tube would be sub-divided to form the smaller tube of the finished size.

In carrying out the tube forming process in accordance with this invention, a tube rolling machine built and constructed in accordance with the prior art such as illustrated in Figs. and 6 may be employed. Such a tube rolling machine comprises a table 4 for receiving and guiding the paper or other material to be rolled into tubes. A feeding arm 5 is translatable back and forth across the table 4 to feed such sheets of paper as 3 to the rolling machinery in predetermined regularity. the feeding arm 5 forces the sheet of paper 3 toward the rolls 6 and 1. The rolls 6 and l are mounted in vertical alinement, the former being biased toward the latter by spring 8 to effect a continuous positive engagement between the surfaces of the two rolls. The roll I is driven in a counter-clockwise direction and the roll 6 in a clockwise direction so that when the forward edge of the sheet material 3 is projected between the rolls it will be drawn forward thereby and advanced to a mandrel 9 which operates to wind the sheet into a tube as is well known in the art. Disposed beneath the roll 1 is a receptacle ll adapted to contain a quantity of suitable adhesive, such as for instance paste, whereby it is possible to transmit a coating of such adhesive to the sheet of paper when it passes thru the It is, of course, understood that the mechanism comprising the feeding arm 5,

the rolls 6 and 1, and the mandrel 9 are driven from a unitary source of power, being directly connected so that they operate in a fixed time relation. For instance it will be observed that the roll 7 is provided with an elevated concentric portion I2 of a circumferential length substantially equal to the width of the sheet of paper 3 and the arm 5 preferably operates in such timed relation with the rolls that the forward edge of a sheet of paper is projected between the rolls 6 and 1 just prior to the time when the forward edge of the elevated concentric surface l2 comes into contact with the roll 5. The elevated concentric surface l2 when in engagement with the roll 6 causes the spring 8 to thus increase the pressure between the rolls which in efiect positively grips the sheet of paper which is passing therebetween at that particular time. The sheet of paper thus positively gripped is fed on toward the rotating mandrel 9 which picks up the forward edge thereof in cooperation with a pick-up l3 to roll the sheet into a tube in a manner well known in the art. It is understood that the structure just described is strictly in accordance with now to be described. Extending between the In accordance with the prior art,

members It is a receptacle l5 adapted to contain a quantity of stearine pitch. The receptacle I5 is provided with a lower closed compartment l6 for containing an electric heating element so that sufficient heat may be applied to the receptacle to reduce the stearine pitch to a molten condition. A roll H has its opposite ends journaled for rotation in the upright members it and is disposed directly above the receptacle I5 in such position that a substantial portion of its surface is immersed in the molten stearine pitch contained in the receptacle H5. The roll i! is provided with an absorbent surface [8 of any suitable material such as is well known in the art.

Another roll I9 having a similar absorbent surface i8 is journaled between the upright members M for rotation tangent to the roll ii and it is thus apparent that stearine pitch attaches itself to the absorbent surface l8 of the roll I! whereby it will be transferred upon rotation thereof to the absorbent surfaces of the roll H). A third roll 2! is mounted for rotation between the upright members l4 and is provided with an elevated concentric surface 22 having an absorbent material thereon. As is clearly illustrated in Figure 6 the rolls l9 and El are positively driven thru gear train 23, 24, 25, directly from the feeding and pasting rolls 6 and I. It is thus apparent that the roll 2| operates in the same fixed time relation which exists between the operation of the feeding arm 5 and the rolls 6 and I so that the roll 2! makes one complete revolution for every sheet of paper which passes thereby and thereunder. It is preferable that the peripheral area of the elevated concentric portion 22 be equal to area over which it is desired to apply the stearine pitch to the sheet of paper 3. Thus the peripheral length of the elevated concentric portion 22 is equal to the distance de as indicated in Fig. 3, and it is, of course, understood that the elevated concentric portion 22 extends the entire length of the roll 2|. The roll 2! is journaled in such position that the surface of the elevated concentric portion 22 becomes successively tangent to the surface of the roll l9 and the surface of a pressrue roll 26, the latter of which is disposed in which position that the plane of the top surface of the table 4 is tangent thereto. The advancing sheet of paper 3 is thus gripped between the surface of the elevated concentric portion 22 of roll 2! and the surface of roll 23, after the forward edge of the paper has passed thereby as is clearly shown in Fig. 5, and the surface of the elevated concentric portion 22 having received a supply of stearine pitch from the roll l9 transfers a quantity of such pitch to the paper passing therebeneath so that the surface of the paper illustrated in Fig. 3 is partially covered with a coating of pitch. The forward end of the sheet 3 moves beneath a stripper 27 disposed in such a position that it prevents the paper from sticking to the surface 22 during continued movement of the latter.

The sheet of paper 3 is then drawn forwardly, after having the desired surface covered with stearine pitch by surface 22 of roll 26 and gripped between the rolls 6 and 1. Here a coating of a suitable adhesive, such. as for instance, paste, is applied to the sheet and it is advanced on to the revolving mandrel 9 where it is wound into tubular form such as shown in Figure 4.

A modified form of a device for applying stearine pitch to the paper is illustrated in Figures '7 and 8 and it may be pointed out that the em- I the pitch applying mechanism illustrated in Figures 6 and 7 to operate in the same regular timed relation with the mechanism of the tube rolling machine. In the embodiment illustrated in 'Figures '7 and 8, the coating of stearine pitch is'applied to the bottom surface of the sheet ofzpaper and for this reason it becomes necessary toprovide this embodiment in such a position that the sheet may be inverted before being engaged by the feeding arm 5. Such mechanism as is necessary to invert the sheet of paper are well known in the art and are accordingly not shown in the drawings. In the embodiment illustrated in Figures 7 and 3 a suitable receptacle 28 is provided for containing the stearine pitch which, like the.

receptacle i5, may or may not be provided with a heating element as is desired. Disposed so that the plane of table 4. is substantially tangent to the surface thereof is a drum 29. The drum 29 is so disposed that the surface thereof is immersed in the stearine pitch contained in the receptacle 28 upon rotation thereof. The roll 29 i rigidly mounted upon shaft 3i which maybe journaled in suitable bearings at opposite sides of the table 4 and is rotatable therewith. It may be pointed out, however, that the drum 2% may be adjusted axially of the shaft 35 to vary the position of the surface of the sheet to be coated relative to the dimensions of the sheet. In this embodiment the width of the roll 29 is equal to the width of the area of stearine pitch applied to the sheet of paper 3 and suitable means is provided to remove the stearine pitch deposited upon the periphery of the drum 29 from the surface thereof, except for a peripheral distance equal to the length b-c as shown in Fig. 3.

The means for preventing the transfer of stearine pitch by said portion of the periphery of the drum 29 includes a pair of cams 32 mounted upon opposite ends of the shaft 3 i' and rotatable therewith. The cams 32 at opposite ends of shaft 3| are similarly disposed relative to the shaft and each have a portion of constant radius extending counter-clockwise from f to g. The portions thereof which exist in the clockwise direction between and g being of lesser radiusias seen in Fig. 8) A pair of arms 33 are pivoted at opposite sides of the table a and are each provided with an arm 34 extending in the direction of cam 32.

On the outer end of arm 33 is provided a follower.

Wheel 35 disposed for engagement with the peripheral surface of the cam 32. Springs 36 are provided which normally bias the arms 33 toward the cam .32. A scraper plate 31 is mounted upon the arms 33 and extends beneath the table 4' across the entire width thereof and in close proximity to the surface of the drum 29. It is apparout that when the parts are in the position shown, the stripper 21 is held out of contact with the surface of the roll 29, however, it is apparent that upon clockwise rotation of the drum 29 the scraper 31 will come into engagement with the surface of the drum 29 between positions g and ,f, it being apparent that between these positions the follower 35 will be permitted to move toward the right under the action 36 to bring the scraper into contact with the drum 29% described.

The surface of the drum 29 is provided with a recess or indentation 38 which lies within the area from which the pitch is removed by the scraper but near to the end thereof. The indentation 38 is disposed to accommodate the forward edge of a sheet of paper 3 to facilitate the start- ..ing'of the samebetween the surface-of roll 29 ..2,oos,922

' bodiment there illustratedmay be substituted for and the surface of the pressure roll'39 in contact therewith. It is thus apparent that the forward edge of the sheet of paper is gripped between the rolls 29 and 39 and advanced for a short distance before the application of stearine pitch begins. Upon forward movement of the roll 29 in the clockwise direction the sheet 3 will be drawn to- Ward theright and 'forced'between the rolls 29 and 39, the former of which will deliver the application of stearine pitch to the under surface of the sheet, until the point g on the surface thereof. is

reached. When the point g is reached the scraper;

31 is then released by the action of'cam 32 and follower 35 to removethe pitch from the remaining surface. This operation is repeated for eachv sheet passed therethru.

As heretofore pointed out the processof applying stearine pitchto sheets of shot shell tube material before the rolling may be carried out by various means. In Figs. 9 and '10 a deviceis illustrated which combines the features of that shown in the preferred embodiment, Figs; and 6, and that shown in Figs. '7 and 8. In the embodiment shown in Figs. 9 and the'roll 4! thereof is' of a width equal to the widthlof, the

area to which it is desired to apply the pitch, i. e., d-e of Fig. 3. This particular embodiment is readily adaptable to the process when the tube material is taken from a roll. With this arrangement, it is thus possible to'continuously-draw a long strip of paper or other tube material beneath the roll iii and apply thereto an application of stearine pitch of the'desiredwidth; 'The strip of paper may subsequently be cut into sheets of the desired length for handling by the customary tube rolling machine.

In Figures 11 and 12 a further modification is shown inwhich a spray 42 is moved across the paper to be treated to deliver a desired application of stearine pitch. 'In this embodiment the member 42 is preferably of a width lir -6 correspending to the width of the area to which the pitch is applied upon the sheet of paper. The

member 42 is oscillatedlengthwise of the sheet of paper by any suitable oscillating -mechanism, such as a cross head 43 and linkage 44. further possible to provide upon the member 42 a number of bristles in order to spread the stearine pitch more evenly across the surface of the paper. 7

In the embodiment illustrated in Fig. 13 the pitch is applied to the paper by a stamping process. In this embodiment a stampingmachine is provided with a head 45 of the same dimension as the area of thepaper to be covered and is oscillatable by any suitable mechanism, such as a linkage 46 between a position in which it engages a pad 41 to receive a supply of the pitch and.

another position in which it is impressed upon the paper to deliver thereto an application of pitch. It may be pointed out that this particular embodiment may be substituted for the feeding arm 5 of the ordinary tube rolling machine since it is readily possible to arrange the head 45 so that it may be moved thru a sufficient amplitude in engagement with the paper 3 to advance the same as has heretofore been accomplished by .like compositions, which are preferably elastic in their nature and possess elasticity, may be'employed as the gas sealing mediun'n It is to be It 'is' understood, however, that it is preferable to employ some substance which will perform the same function as the waxes, as heretofore used, in cooling the tube upon penetration of the hot powder gases. This result may, however, be accomplished not only by taking advantage of the latent heat of the gas sealing medium, but also in substances which have a higher specific heat than paper the same result will be accomplished, since the tube is maintained at a temperature below the ignition point.

As another embodiment of this invention, a sheet of tube forming .material of a thickness less than that usually employed may be first coated with the gas sealing substance such as stearine pitch and after the application thereof, another thin sheet of material may be applied over the film of stearine pitch so that a composite sheet results, the thickness of which is preferably the same as the single sheets employed in the embodiments of this invention hereinbefore described. Furthermore, the stearine pitch may be initially applied to a thin sheet of paper and the film subsequently covered over by another thin sheet so that in effect a paper tube is formed having on the interior thereof a film of the gas sealing medium. This fiat tube containing the gas sealing medium may then be laid on the sheet of tube forming material just prior to the rolling process thereof as an inlay, substantially in the same manner as that described in our copending application Serial No. 511,668, filed January 28, 1931, for inserting a metallic strip in the wall of of a shot shell tube. By this latter process, it is apparent that an isolated body of the gas sealing medium is provided between the convolutions of the paper, and as described with reference to the preferred embodiments of this invention, the film of gas sealing substance preferably extends for the full circumference of the tube with a slight overlap.

Thus in accordance with this invention a sheet of tube forming material, after having been coated with a suitable plastic substance such as stearine pitch, is rolled into tube form and in accordance with general practice is of such length as to form a plurality of sized shot shell tubes. Accordingly the tube, after having been rolled upon a mandrel, such as 9, is sub-divided into a plurality of tubes of the desired length, each having therein a complete convolution of a gas sealing medium. After the tubes have been sized, it is desirable that they be given a coating of water proofing material, such as for instance a nitrocellulose lacquer, the function of which is to prevent the entrance of moisture through the outer convolutions of the tube forming material of the tube.

It is thus apparent that the various modifications shown and described are each capable of being used in conjunction with the customary tube rolling machine for carrying out the process of this invention, but since it is apparent that many other modifications will present themselves to those skilled in the art and which may be readily adaptable for carrying out the process of this invention, it is to be distinctly understood that the embodiments here shown and described are merely illustrative and shall not be construed in a limiting sense.

While stearine pitch is particularly suitable and efficient to provide a seal between the convolutions of a paper shell tube, it will be understood that other pitches and other plastic substances having the desired characteristics, may be employed to attain, to an extent at least, the objects and purposes of this invention. It is to be understood that the term stearine pitch and even the term paper are used in a descriptive and not in a limitative sense.

Since it is possible for the process and product of this invention to be modified without departing from the spirit of the invention, it is to be distinctly understood that such modifications and the use of sub-processes which, although not specifically described herein, are contemplated by and Within the scope of the appended claims.

It is to be further understood that the foregoing description and the accompanying drawings are merely illustrative of the preferred embodiment of the process and apparatus of this invention and shall not be construed in a limiting sense.

Having thus described the invention what is claimed is:

1. A shot shell having a tube composed of convolutions, one of said convultions being coated with stearine pitch.

2. A shot shell having a tube composed of convolutions of paper with stearine pitch between convolutions.

3. A shot shell having a tube containing a nonpenetrating gas-sealing medium in the wall thereof, said medium remaining sufiiciently plastic to permit the tube to expand under the force of firing.

4. A shot shell having a tube composed of convolutions of paper, one of said convolutions being coated with a nonpenetrating gas-sealing medium in the wall thereof, said medium remaining sufiiciently plastic to permit the tube to expand under the force of firing.

5. A shot shell tube composed of convolutions of paper, one of said convolutions being coated with a layer of asphaltum.

JOHN M. OLIN. ALFONS G. SCHURICHT. 

